diff --git a/firmware/controllers/engine_cycle/fuel_schedule.cpp b/firmware/controllers/engine_cycle/fuel_schedule.cpp
index 7afb101354..83ca872bf3 100644
--- a/firmware/controllers/engine_cycle/fuel_schedule.cpp
+++ b/firmware/controllers/engine_cycle/fuel_schedule.cpp
@@ -129,8 +129,15 @@ bool InjectionEvent::updateInjectionAngle() {
  */
 bool FuelSchedule::addFuelEventsForCylinder(int i) {
 	InjectionEvent *ev = &elements[i];
+#if EFU_UNIT_TEST
+	if (ev->ownIndex != i)
+	  throw std::logic_error("index issue");
+#endif
+	return ev->update();
+}
 
-	bool updatedAngle = ev->updateInjectionAngle();
+bool InjectionEvent::update() {
+	bool updatedAngle = updateInjectionAngle();
 
 	if (!updatedAngle) {
 		return false;
@@ -145,7 +152,7 @@ bool FuelSchedule::addFuelEventsForCylinder(int i) {
 		injectorIndex = 0;
 	} else if (mode == IM_SEQUENTIAL || mode == IM_BATCH) {
 		// Map order index -> cylinder index (firing order)
-		injectorIndex = getCylinderId(i) - 1;
+		injectorIndex = getCylinderId(ownIndex) - 1;
 	} else {
 		firmwareError(ObdCode::CUSTOM_OBD_UNEXPECTED_INJECTION_MODE, "Unexpected injection mode %d", mode);
 		injectorIndex = 0;
@@ -160,7 +167,7 @@ bool FuelSchedule::addFuelEventsForCylinder(int i) {
 		// Compute the position of this cylinder's twin in the firing order
 		// Each injector gets fired as a primary (the same as sequential), but also
 		// fires the injector 360 degrees later in the firing order.
-		int secondOrder = (i + (engineConfiguration->cylindersCount / 2)) % engineConfiguration->cylindersCount;
+		int secondOrder = (ownIndex + (engineConfiguration->cylindersCount / 2)) % engineConfiguration->cylindersCount;
 		int secondIndex = getCylinderId(secondOrder) - 1;
 		secondOutput = &enginePins.injectors[secondIndex];
 	} else {
@@ -168,13 +175,12 @@ bool FuelSchedule::addFuelEventsForCylinder(int i) {
 	}
 
 	InjectorOutputPin *output = &enginePins.injectors[injectorIndex];
-	bool isSimultaneous = mode == IM_SIMULTANEOUS;
 
-	ev->outputs[0] = output;
-	ev->outputs[1] = secondOutput;
-	ev->isSimultaneous = isSimultaneous;
+	outputs[0] = output;
+	outputs[1] = secondOutput;
+	isSimultaneous = mode == IM_SIMULTANEOUS;
 	// Stash the cylinder number so we can select the correct fueling bank later
-	ev->cylinderNumber = injectorIndex;
+	cylinderNumber = injectorIndex;
 
 	if (!isSimultaneous && !output->isInitialized()) {
 		// todo: extract method for this index math
diff --git a/firmware/controllers/engine_cycle/fuel_schedule.h b/firmware/controllers/engine_cycle/fuel_schedule.h
index 571fddce89..d734624acd 100644
--- a/firmware/controllers/engine_cycle/fuel_schedule.h
+++ b/firmware/controllers/engine_cycle/fuel_schedule.h
@@ -18,6 +18,8 @@ class InjectionEvent {
 public:
 	InjectionEvent();
 
+	bool update();
+
 	// Update the injection start angle
 	bool updateInjectionAngle();